Compress PDF Online Free
Compress PDF files online with BuBird PDF Studio. Use the quality slider to control how much to compress, batch-compress multiple PDFs at once, and compress again for even smaller results — all in your browser, no uploads required.
How to use this tool
Step 1
Upload one or more PDF files — drag & drop or click to select (up to 10 files).
Step 2
Adjust the quality slider from 0 (maximum compression) to 100 (near-lossless) per file.
Step 3
Use Quick Presets — Extreme, Balanced, or High Quality — for instant settings.
Step 4
Click Compress All to start batch compression. Live progress shows for each file.
Step 5
Download each compressed file individually or use Download All for batch download.
Step 6
Not small enough? Adjust the slider lower and click Compress More to compress again.
Why choose BuBird
Quality Slider 0–100
Precise compression control from Ultra Extreme to Near Lossless. You decide the balance between file size and image quality.
Multi-File Batch Compression
Upload up to 10 PDFs at once. Each file compresses simultaneously with its own progress bar and quality setting.
Compress Again Feature
After first compression, adjust the slider lower and click Compress More. Compress the same file multiple times until you reach the target size.
Live Progress Per File
Watch real-time progress for each PDF — image count, compression step, and percentage complete — all visible as compression runs.
Files Never Leave Your Device
All compression runs in your browser using pdf-lib and the Canvas API. No server uploads, no cloud processing, complete privacy.
Cumulative Savings Stats
See original size, compressed size, percentage saved, and savings per compression round clearly displayed for every file.
Common use cases
Email Attachments
Reduce PDF size below email attachment limits (5 MB, 10 MB, 25 MB) for Gmail, Outlook and corporate mail servers.
Job Applications & Resumes
Compress certificates, portfolios and resumes to meet job board and government portal upload size restrictions.
WhatsApp & Messaging Apps
Reduce PDF file size to share documents easily via WhatsApp, Telegram and other messaging apps with file size limits.
Website PDF Downloads
Compress PDF documents hosted on your website to reduce bandwidth usage and improve download speed for visitors.
Cloud Storage Optimization
Shrink large PDF archives to save storage quota in Google Drive, Dropbox, OneDrive and other cloud storage services.
Scanned Document Compression
Compress scanned PDF files that contain large JPEG images to reduce file size while keeping text readable.
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